Shock absorbing device



Aug.-l8, 1931. R. L. @Russ SHOCK ABSORBING DEVICE Filed oct. 22, 41928 wdlzzz" ATTORNEYS.

. INVENT 'Patterned Aug. 1s, 1931 UNITED STATES PATENT 'oFEICE RAYMOND. r.. Gauss, E SAN EEANCIsCo, CaLrronNIA; LABA E. Gauss ADMIN- rsrnA'rRIx CE sAIn RAYMOND L. Gauss, nECEAsED, AssreNon, EY mEsNE AssIGN- MENTS, 'ro CALIFORNIA BANK, oE Los ANGELES, CALIFORNIA, A CORPORATION sHoCx ABsoaEING DEVICE Application led ctober 22, 1928. Serial No. 818,987.

M present invention relates to pneumatic shocl absorbing devices and more particularly 'to an improved device of this character suitable for use in connection with the landing gear of aeroplanes.

In a co-pending application filed October 22, 1928, and bearing Serial No. 313,986'I have disclqsed an improved shock absorbing strut for aeroplanes wherein I illustrate a certain embodiment of my invention.

It is therefore an object 'of my presentinvention ,to provide an improved device of the above Character having a pneumatic air cushion and means for checkin rebound in a manner different from that gli above referred to a plication.

For a better un erstandmg of vmy inventionkreference should be had to the accom panylng drawings wherein I have shown by way of illustration and not of limitation, one manner of attaching my improved device and also the internal construction thereof.

In these drawings- [Figure 1 is a front view in elevation of an aeroplane equipped with my improved shock absorbing device,

Figure 2 is a longitudinal sectional view of my device in its extended condition,

Figure 3 is a view similar `to vthat of-Figure 2 showing the parts in their collapsed condition',

Figure 4 is a fragmentary sectional view of a detail of my device, and

Figure 5 is a view looking u ward at the bottom of the portion shown in igure 4.

In Figure 1, 1() designates the fuselage of an aeroplane having a wing structure 11 of the monoplane type. The wing structure 11 is supported UPOII. the fuselage 10 by means of suitable struts 12 and 13 and Connected to the fuselage-at its central point I show a wheel axle 14 which is in two parts, each part being hinged at its inner end to the fuselage. Mounted upon the axles 14 are the usual landing wheels 15 and interposed' between the axles 14 .adjacent the wmheels 15, I propose to mountmy improve shock absorbing device or strut which I have designated by the numeral 16. The struts 16 are secured to the-struts 12 at their upper ends with a'hinged con! sclosed in my nection so that relative movement therebetween will be possible and at their point of attachment with' the axle there is also a hin ed connection.

iththis arrangement it will be seen that I when the wheels are in Contact, with the ground, the total weight of the plane will be carried upon the shock absorbing device 16 and that when thewheels' leave the ground, the device 16 will, under the influence of the air pressure therein, extend itself so that the wheels will assume a position further removed from the plane than here' shown. This will permit the wheels to establish contact with the ground in landing before the weight ofthe plane is assumed thereby and, as a result, the weight of the plane Will'be slowlyv taken up by theair cushion as will hereinafter appear andthus the first shock and impact of landing will be absorbed lby the full length of the air cushion, the pressure within the pneumatic cylinder starting at a low value and gradually increasing as the ystrut is compressed, thereby Checking the downward motion of the plane in direct proportion to the force at which. a landing is made.

The further aspect of my invention with` respect to the rebound preventing characteristics thereof will best be understood in con? nection with a description of the remaining figures of the drawings. y

In. these figures of the drawings it will be seen that the shockabsorbing device or strut 16 is comprised ofan inverted pneumatic Cylinder 20 havinga pistonjhead 21 adapted to operate therein when pressure is brought to bear thereupon by 'reason of external forces.y The piston head 21 is shown as provided with a hollow piston rod 22 and extending from the top of the cylinder 20 cen# trally thereof I show arod 23 which carries of the cylinder 20 I provide a suitable cyl.-

ing the escape stand the ressures exerted from inder head 28 which is screw-threaded into the end-of the cylinder 20.. The cylinder head 28 carries a suitable-packing 29 for preventof oil from my device at this iston head21 is also shown as asket 30 which exges so as to withabove and ead 26'is shown as` provided with point. The provided wit a packing tends lupwardly at its e the piston 4two acking gaskets 31 and 32 which are rolle at their edges so as to project respectively upwardly and downwardly. This arrangement of gaskets is to insure against the passage of air or oil in either direction about this piston head. At the interior of the piston head 26 where the piston rod 22 projects therethrough there is also provided a further packing 33 which is'adapted to prevent the escape of oil from the interior of the cylinder rods and the cylinder 20. In' order to rod 27. Adjacent the o is ada ted to be set for the pur a pressure or vacuum existing withprevent in the c'linder 2O below the piston head 26,

I rovi e openings or vents 34.

eferring now specifically to the interior construction of the hollow piston rods 22 and 27, it will be seen that the piston rod 22 is provided at a point adjacent the head 21 with a bearing 35 which slides upon the rod 23. This bearing is mounted centrally of the interior o ning of the rod 22 by means of suitable we s so that a passage of oil may be maintained therearound. The function of this bearing is to gluide the rod 23 and act in conjunction with t e enlarged head 24 to revent the piston head 21 from movin be ow the point where the bearing 35 and t e head 24 engage. At the'lower end -of the piston rod 22 I provide an opening 36 through whichoil may pass in'to the interior of the hollow piston ning 36 mounted is a screw 38 which se yof controlling t e llow of oil through t e opening 36. The `lower end ofthe hollow piston rod 27 is provided with a air of ears 39 by means of which this end o Ai'ny improved strut may attached to the wheel axle and at the upper upon a suitable support 3 end of my devise there is also provided a pair which air under pressure may be F5 which the oil 25 may be int "of similar ears 40 for the purposeA of attaching my device to frame. At this end of the cylinder 20 show a suitable pneumatic valve 41' through int into the cylinder and adjacent thereto is a removable plug 42 in an o iilg through .be assumed that With the parts of my the aeroplane fuselage or also reduced The o ration of this embodiment of my improve shock absorbing strut in connection with an aeroplane is as follows: It is to the cylinder 20 has been pumped u 4with air to a suitable pressure 'and that t e plane to which itis attached is in the air and about to make a landing. Un-

' der these conditions the parts of my improved device are assumed to be in the positions in which they are illustrated in-Figure 2 of the drawin s. From this figure of the drawings it will e seen that the piston head 21 is in its lowermost position within the cylinder 2O with its hollow piston rod 22 projecting below the lower end of the cylinder 20. It will also be seen that the cylinder head 26 has also -assumed its lowermost position so that its cooperating piston rod 27 will be extended to its outermost pos'tion. The piston head 2 1 will be held in the position here shown by reason of the pressure exerted thereupon by the air withiirthe cylinder 20 and the osition of the Eiston head 26 as shown will maintained y reason of ressure exerted from within the cylinder 20 t rough the column of oil which extends into the'hollow piston rods 22 and 27 A further force tending to move the piston head 26and its attached piston rod 27 downwardly will, of course, be exerted' by the weight of the wheels 15 and their axles 14. device in the position shown and under the conditions assumed, when the wheels 15 ofthe aeroplane contact with the ground as in landing, the first imact caused thereby will be taken up by the ull length of deflection of the air within the cylinder 20. The deflection in this case will be determined by the force of the impact and the pressure of the air maintained within the cylinder 20. After the wheels have established contact with the ground, the air cushion will gradually pick up the weight of the machine and at the same time thehollow piston rod 27 and its piston head 26 will slowy move u wardly over the piston rod The rate o .this movement of the piston rod 27 will be determined by the rate of l'luid flow through the opening 36. This latter movement will permit the plane to settle slowly sud en impact or uneven ground,

be denciea to rebound will be eliminated as the wheeli will be carried out of contact with the und before the piston, 27 can again extend itself. By this arrangement all rebound will be eiectively controlled hydraulically without sicriicing to any degree the eciency of the air cushion provided in the cylinder 20. After the' weight of the plane has been transferred to the wheels 15 as when the plane has assumed a relatively slow speed or has stopped, the parts of my improved device will assume the position substantially `as shown in Figure 3.I When the parts are in this position it will be seen that the piston head 21 and within the cylinder 20. This Figure of the drawing also illustrates the position of the parts during the taxing period of the plane and from an inspection it will be seen that the entire weight of the plane will be supported` u on the cushions of compressed air within t e cylinders 20 and that, should the plane risefrom the ground, the air pressure within the cylinder will extend the device in proportion to the weifrht removed from thel wheels and, as a result, provide a cushion wherein the greatest amount of iiexibility under that particular weight will be automatically produced, thus relieving the plane of all jar and rack when taxiing'over rough ground. In takin oil', as the lane tends to rise, the device wi l extend itsel and thus allow the compressed'air in the cylinder 20 to expand and thus permit the device to support a portion of the load of the plane until the wheels have finally left the ound. At this time the 'hollow pistons 22 an 27, by

' reason of the oil contained therein, will slowly extend themselves with respect to each other at a rate depending upon the flow of fluid therebetween through the opening 36 and, should it happen that the wheels again contact with the ground either before or after these piston rods have extended themselves, the air cushion within the cylinder 20 will be immediately 'brou ht into playv without necessitatin a loss oi altitude by the plane. It will be un erstood that the size of the opening36 may4 be varied and that the screw 37 may also be adjusted to var the flow of liquid therethrough as determine by the particular application and conditions under whichlthe paricular shock absorbing device is tobe use sible to eiect a much more rapid take-ofi and shorter landings than is generall possible with the ordina type of lan ing ear. lThese characteristics I attribute particuarly to the fact that the a/ir cushion comes into play immediatel when the wheels touchthe ground and gra ually assumes the weight of the machine, while at the same time the hydraulic features asdescribed in connection with the hollow piston rods 22 and 27 ypermit the machine to settle with the wheels always in contact with the ground during this riod and also reduce the possibilities of re ound.

From the above it will be seen that I have produced a new and improved type of shock I have found-that my device makes itwposabsorbin i device for aeroplanes and the like, and, whi e I have shown in the accompanydrawings a preferred embodiment there-' in odg I desire to have it understood that many 'modiiications thereof will readily suggest themselves to those skilled in the art to which my invention appertains without departing from the spirit and scope of the invention as delined in the appended claims. Y

Having thus described my invention, what I claim and desire to secure by Letters Patent isy 1. In combination with a shock absorbing air spring for aeroplane landing gear comprising a pneumatic cylinder and a piston head operating therein, a hollow piston rod carried by said piston head, a second piston head in said cylinder and surrounding said hollow piston rod, and a second hollow piston rod for said second piston head telescoping over said first piston rod, said hollow piston rodsbeing adapted to contain liquid and cooperate with each uother to prevent rebound when said shock absorbing spring is compressed due to impact with the ground in landing. I

2. A shock absorbing devi/ce for aeroplane landing gear comprising a cylinder adapted to contain air under pressure, a piston adapted to operate within saidcylinder and compress said air when pressure is exerted thereupon, a hollow piston rod having its interior communicating with said cylinder, a plunger member secured to the end of said c linder and projecting into' said hollow piston' rod, a second piston located in said ylinder below said 4first piston, and a second hollow piston rod telescoping over said rst hollow piston` rod 4and cooperating with said first piston rod to check rebound, the interior of said first and second hollow piston rods being incommunication with the pressure chamlber of said cylinder and adapted to contain a liquid. l

3. In a shock absorbing device of the pneumatic cylinder type, the combination of a cylinder adapted to contain air under pressure, a piston operating within said cylinder, a hollow piston rod secured to said cylinder, .a sto for limiting the outward movement of said piston to a point intermediate the ends of saidcylinder, a second piston o erating within said cylinder belowI said rst piston, a second hollow piston rod telesco ing over said first piston rod, said rst hdllow piston rod being in communication with thepressure chamber of. said cylinder and ada ted to containoil, and a by-pass between sai first vand second hollow vpiston rods whereby said' oil may iiow in .a' restricted mannerv between said hollow piston rods to thereby check rebound when said shock ab-v sorbing device is compressed due to impact with the groundin landing.

- 4. Ina shock absorbingdevice of the pneu-l` no l ' said hollow matic cylinder type, ythe combination of a cylinder adapted to sure, a piston operating within said cylinder, a hollow piston rod secured to said cylmder a stop for limiting the outward movement oi said piston to a point intermediate the ends of said cylinder, a second piston operating within said cylinder below saidrst piston, a second hollow piston rod telescoping over said {irst piston rod, said first hollow piston rod being in communication with the pressure chamber of said cylinder and adapted to contain oil, and a communicating assageway between said Vfirst and secon hollow piston rods whereby oil may flow therebetween to permit the pressurewithin said cylinder to be applied through said oil to extend iston rods when the load is removed there rom.

RAYMOND L; GRUss.

1,&19,414

contain air under pres- 4 

